Keyboard Tester
Press any key to verify it registers correctly.
Press any key to see its details
0 of 74 keys tested
A physical keyboard is required to use this tool.
When to Use a Keyboard Tester
Use this tool to verify a new keyboard works correctly out of the box, check for dead keys after a spill or physical damage, test N-key rollover for gaming keyboards, diagnose ghosting issues where certain key combinations don't register, and verify function keys and modifier keys are mapping correctly.
Understanding Key Events
event.key is the character produced by the key press — it changes with modifier keys (Shift turns "a" into "A"). event.code is the physical key location on the keyboard — it stays the same regardless of layout or modifiers ("KeyA" is always the leftmost home-row key). keyCode is a legacy numeric identifier that is deprecated but still used by some older applications.
Common Keyboard Problems
Ghosting occurs when pressing multiple keys simultaneously causes phantom key presses or dropped inputs. Chattering is when a single key press registers multiple times due to worn switch contacts. Dead keys simply don't register at all — often caused by physical damage, liquid spills, or manufacturing defects.